Cooling Device

ABSTRACT

A cooling device comprising a rotating part ( 1 ) provided with an internal space ( 3 ) intended for the transport of cooling liquid and provided with external fins ( 4 ) intended for the transport of gas along at least a section of the rotating part. The rotating part is symmetrical in rotation and revolves around an axis of rotation ( 2 ). The rotating part comprises a cooling liquid pump section ( 5 ), a fan section ( 6 ), and between these an intermediate section ( 7 ) arranged around the axis of rotation, where the fan section has a basic shape of a radially extended plate ( 15 ), wherein the flow of cooling liquid enters at the pump section from an object to be cooled, proceeds through the intermediate section and turns back in the vicinity of the periphery ( 17 ) of the fan section, in order to once again pass the intermediate section and then be pumped back to the object by means of the pump section.

The present invention relates to a cooling device comprising a rotatingpart provided with an internal space intended for liquid transport ofcooling liquid, and provided with external fins intended for airtransport along at least a section of the rotating part. For example,the cooling device is intended for vehicle engines, such as combustionengines or electric engines, or other objects in need of heat exchangebetween a liquid and a gas, such as air. One example of such objects isheat pumps. As readily understood by the skilled person, it is notnecessarily a matter of cooling, but any kind of heat exchanging may berelevant.

STATE OF THE ART

Conventional systems for cooling, e.g., vehicle engines of today arebased on liquid cooled engine blocks and a radiator. The system alsoincludes a liquid pump and a radiator fan. The conventional systems areassociated with obvious drawbacks by being comprised of severaldifferent, typically expensive, components requiring hose couplingsbetween them, and by requiring that a vacuum is applied in the system inorder to avoid air bubbles in the system. Furthermore, the system takesup a great deal of space.

SUMMARY OF THE INVENTION

It is an object of the present invention to avoid the drawbacksmentioned above. This can be solved by means of a cooling deviceaccording to claim 1.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described by means of exemplaryembodiments of the invention and with reference to the attacheddrawings, in which:

FIG. 1 illustrates an embodiment of the present invention,

FIG. 2 a illustrates a first embodiment of the location of the externalfins on the plate (only a few fins are shown),

FIG. 2 b illustrates a partial side view of the first embodiment,

FIG. 3 a illustrates a second embodiment of the location of the externalfins on the plate (only a few fins are shown),

FIG. 3 b illustrates a cross section A-A of the second embodiment,

FIG. 4 a illustrates a third embodiment of the location of the externalfins on the plate (only a few fins are shown),

FIG. 4 b illustrates a partial side view of the third embodiment,

FIG. 5 a illustrates a fourth embodiment of the location of the externalfins on the plate (only a few fins are shown),

FIG. 5 b illustrates a cross section A-A of the fourth embodiment,

FIG. 6 a illustrates a fifth embodiment of the location of the externalfins on the plate (only a few fins are shown),

FIG. 6 b illustrates a cross section A-A of the fifth embodiment,

FIG. 7 a illustrates a second embodiment of the present invention havingan air pervious material (only a few fins are shown),

FIG. 7 b illustrates a cross section A-A of the second embodiment, and

FIG. 8 illustrates a side view of a third embodiment of the presentinvention having a corrugated plate.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In FIG. 1, an embodiment of a cooling device according to the presentinvention is shown. The cooling device comprises a rotating part 1 beingsymmetrical in rotation that can be revolved around an axis of rotation2 by means of driving, e.g., the object or the engine to be cooled or anelectrical engine. The rotating part 1 has an internal space 3 intendedfor liquid transport of cooling liquid through the rotating part, inorder to achieve the actual heat exchange between warm cooling liquidcoming from the engine to be cooled which is conducted through theinternal space 3 of the rotating part 1, whereby the heat is absorbedand discharged to the surrounding air, such that chilled cooling liquidcan flow back into the engine in order to cool it once again.

The rotating part 1 is further provided with external fins 4 in order toincrease the transport of air along at least a section of the rotatingpart 1, and the fins 4 may also form an enlarged heat exchanging surfacetowards surrounding gas/air.

The rotating part 1 comprises three main sections, namely a coolingliquid pump section 5, a fan section 6 and an intermediate section 7connecting the two former sections 5 and 6, the three sections beingarranged around the axis of rotation 2. The cooling liquid pump section5 is provided with an impeller 8 pumping the cooling liquid back againinto the engine or object when cooling is needed or initially via therotating part 1 if desired, before the cooling liquid returns to theengine or object.

Preferably, a fixed housing 9 is provided around the rotating pumpsection 5, its impeller 8 and the rotating part 1 being journalled inthe fixed housing 9 by means of one or more bearings 10, such as ballbearings, and provided with sealings 11 against the cooling liquid. Anoutlet 12 from the housing 9 directs the cooling liquid back to theengine or object to be cooled.

The intermediate section 7 is provided with at least two internalchannels, optionally arranged concentrically along the axis of rotation2, an inlet channel 13 for incoming cooling liquid to be cooled insidethe rotating part 1, and an outlet channel 14 for the cooling liquid tobe pumped back to the engine via the pump section 5. The intermediatesection 7 may be extremely short and is regarded as merely an inlet oroutlet, respectively, from the fan section 6.

The fan section 6 has the basic form of a radially extending plate 15,in its centre on a first side 18 of the plate 15 being interconnectedwith the intermediate section 7. The interconnection is made such thatthe inlet channel 13 and the outlet channel 14 are interconnected withat least one cooling liquid channel 16 inside the plate 15 which atleast conducts the cooling liquid from the inlet channel 13 in thevicinity of the centre of the plate 15 out to its periphery 17. At leastone cooling liquid channel 21 conducts the cooling liquid back towardsthe centre to the outlet channel 14 in the intermediate section 7.

The cooling liquid channels 16 and 21 may be a rotary symmetricalcavity, but may also be, e.g., subdivided peripherally or as radialchannels. It is not required that the cooling liquid channels 16 and 21have the same form. A partition wall 22 separates the channels 16 and21, and the channels 16 and 21 are interconnected by means of a sectionhaving at least one channel 23 in the axial direction at the periphery17.

The plate 15 is provided with external fins 4 on a second side 19opposite the first side 18, and/or on the first side 18, and/or alongits periphery 17. The external fins 4 are arranged to provide a fanaction at the fan section 6 such that more air or gas comes into contactwith the fan section 6, wherein a greater level of heat exchange isobtained. As mentioned above, the fins 4 may also be utilized to form anenlarged heat exchanging surface.

The fins 4 may be arranged radially and axially, see FIGS. 2 a+b, orslanting down radially over the plate 15 at an angle to the axis 2 asseen in the rotary direction, in order to force down the air being at ahigher level over the plate surface 15 towards the surface, see FIGS. 3a+b. The contrary is also possible, i.e. when the fins 4 are inclined inthe opposite direction as seen in the rotary direction, such that theair is exhausted away from the plate surface 15 and is replaced by newair, which may be favourable also for the heat exchange action.

Preferably, regardless of the angle to the axis 2, the fins 4 are alsocurved radially, like fans are formed conventionally, in order toincrease its fan action, see FIGS. 4 a+b and 5 a+b. Another exemplarydesign of the external fins 4 is when being broken up with alternatinginclinations to the axis 2 radially, see FIGS. 6 a+b. Also in thisembodiment, it is possible to design the fins curved radially (notshown).

In order to enable the passage of air adjacent to the plate 15 at itsoutermost periphery 17, a slit may be provided between the plate 15 andthe fin 4 at the radially outer section of the fin 4.

According to a second embodiment of the fan section 6, see FIG. 7, anumber of blocks arranged in rotational symmetry (not shown), or acircular section 20 of an air pervious material having favourable heatexchanging properties, such as a sintered material of copper, aluminiumor Carbon Graphite Foam or a conductive plastic material, are arrangedradially inside regular fan fins 4, which fan fins 4 can be displacedradially outwards. The cooling liquid channel(s) 16 and/or 21 in theplate 15 may then be branched, e.g. by means of pipes 24, such that atleast a certain partial flow of the cooling liquid flow runs throughthese blocks or circular section 20. Cooling liquid channels in the formof pipes may in that case be “incorporated” in the air pervious materialby means of, e.g., forming by casting, laser working or drilling.Inserting cooling liquid channels in the air pervious material throughthe blocks or circular section 20 can also be effected by formingcavities in the material, without the use of pipes.

The radially inner section of the blocks or circular section 20 orinternal surface facing the centre, may preferably be formed with acertain axial inclination, e.g. by being shaped conically or with acertain angle of repose, thereby allowing larger objects such as leaves,in the case they tend to settle upon the blocks or circular section 20,to pass by. This implies that the shape of the interior surface is givensuch an inclination along the radius relative to the axis of rotation,that the frictional forces or other forces acting to maintain theselarger objects on the radial interior surfaces of the blocks, becomesmaller than the ejecting centrifugal forces acting at occurringrotation speeds.

According to a third embodiment, the plate 15 has a corrugated shape inorder to increase the area of contact and/or thermal transmissiontowards the air, see FIG. 8. As mentioned above, different types of finscan be arranged on the corrugated plate 15.

According to an embodiment not shown, the orifice size of the airchannel inlet is formed such that particles of dirt, mud and dust arenot inclined to get caught and be accumulated in the inlet. Preferably,the size of the orifice is a few millimetres or greater. The inlet ispreferably formed with angles of repose such that the centrifugal forceexceeds the frictional force at occurring rotation speeds, therebypreventing the accumulation of particles of dirt, mud and dust.

It is known per se that rotating plates containing liquid to be heatexchanged towards air can be provided with pipes protruding from theplate in order to increase the surface of heat transmission. It is alsoknown from GB 1 435 435 that such pipes protruding from the plate may beprovided with annular sheets mounted on the pipes protruding from theplate or rotating body, such that a laminated bundle is obtained aroundthe pipes. This is to accomplish a surface enlargement from the pipestowards the surrounding air flow. However, a drawback with such a designis that the pipes, which may be considered to extend in the liquid flowdirection out from the plate, are re-directed at the outermost positionof the plate where they extend roughly parallel to the plate, and arethereafter given an inward extension towards the plate again. At thearea of re-direction, fin members are lacking, or the fin membersbecomes considerably sparser as a result from being positionedperpendicular to the pipe extension due to manufacturing aspects. Ofcourse, it is possible to attach fin members along the pipe extension inthis area, but the geometrical heat exchange surface of the fin isreduced for each pipe length. Furthermore, this requires a verycomplicated fabrication process, and is therefore not used. On the otherhand, if fin members positioned perpendicularly around the pipe aredesired in this area, these members require inward space towards theplate, thereby reducing the fin members located around the parts of thepipe protruding from the plate, on the whole resulting in lost surfaceof heat transmission in the remaining parts of the pipe.

The present invention with surface-enlarging porous air pervious blocksaround pipes protruding from plates, such as being described herein,provides for equal surface-enlargement in all directions of the pipe.Furthermore, the pipe may be given a zigzag-shaped radial extensionalong and transversally the rotating plate. Plural changes of directionprovide for further benefits as regards the heat transmission inside thepipe. From thermodynamic laws, it is known that a change of directionfor a fluid inside a pipe involves enhanced heat transmission betweenthe fluid and the pipe wall. By means of the present invention, this isutilized such that the heat transmission in the pipe becomes moreeffective, as compared to the technique according to the above-mentionedGB 1 435 435 where complex pipe shapes cannot be used.

The invention is not limited to the various described and shownembodiments, but variations thereof are naturally possible within thescope of claim 1.

1-8. (canceled)
 9. A heat-exchanging device comprising a rotating partprovided with an internal space intended for the transport of liquid andprovided with external fins intended for the transport of gas along atleast a section of the rotating part, wherein the rotating part isdesigned symmetrical in rotation around an axis of rotation, andcomprises a liquid pump section, a fan section, and between these anintermediate section arranged around the axis of rotation, where the fansection has a basic shape of a radially extended plate, where in theflow of liquid in use enters at the pump section from the object to becooled or heated, proceeds through the intermediate section and turnsback in the vicinity of the periphery of the fan section, in order toonce again pass the intermediate section and then pumped back to theobject by means of the pump section, and a number of blocks arranged inrotational symmetry or circular section of an air pervious materialhaving favorable heat exchanging properties, such as a sintered materialof copper, aluminum or Carbon Graphite Foam or a conductive plasticmaterial, are arranged radially inside regular fan fins.
 10. Aheat-exchanging device according to claim 1, in which the external finsare arranged radially and deflecting towards the plate at an angle tothe axis of rotation.
 11. A heat-exchanging device according to claim 1,in which the plate has a corrugated shape.
 12. A heat-exchanging deviceaccording to claim 1, wherein said blocks or circular section have/hasan axially inclined shape in relation to the radial extension of theheat-exchanging device.
 13. A heat-exchanging device according to claim1, wherein liquid channels are formed in said blocks or circularsection, such that at least a part of said liquid flow can run throughthe blocks or circular section.
 14. A heat-exchanging device accordingto claim 5, wherein the liquid channels are formed as pipes or cavitiesin the air pervious material having a plurality of changes of directionfor enhanced heat transmission.
 15. A heat-exchanging device accordingto claim 6, wherein said pipes have a zigzag form extending radiallyalong and transversally to said plate.
 16. A heat-exchanging deviceaccording to claim 1, wherein air channels are arranged in the airpervious material with smooth changes of direction in order to allow anyoccurring particles of dust to pass.